Week 4 is often when a test turns positive, around the time your period would have come. You may feel nothing yet, or already feel quietly different.
Your baby this week
- Settling in
- The tiny ball of cells has burrowed into the lining of your uterus, where it will grow for the months ahead.
- Three layers
- Its cells are sorting into three layers that will become every part of your baby, from skin and brain to heart and gut.
- Support system
- The early placenta is forming, and starting to make the hormone a pregnancy test picks up.
What you might notice
- A missed period, often the first sign.
- Tender, fuller breasts, a bit like before a period.
- Tiredness that arrives early and can feel out of proportion.
- Light spotting. A little around now can be normal; heavier bleeding or pain is in the list below.
Call your midwife, doctor or early pregnancy unit today if
- You have bleeding, or cramping pain low in your belly
- You have sharp pain on one side, pain in the tip of your shoulder, or you feel faint
- You're being sick so often you can't keep fluids down
- You have a fever, or it burns or stings when you pee
If the pain is severe or you feel faint, call emergency services.
Coming up
Get in touch with a midwife or doctor to arrange your first appointment. What happens at each visit.
Most guidance recommends taking folic acid every day. Ask which dose is right for you.
Questions to bring to your next appointment
- When should my first appointment be, and what will happen at it?
- Are the medicines and supplements I already take okay to continue?
- Is the folic acid dose I'm taking right for me?
For your partner
These early weeks are often the hardest and the least visible. Take on a meal or an errand without being asked, and keep the news as private as they want it kept.
NUGA follows you week by week
Enter your due date once and NUGA knows you're at week 4. The day before each appointment, it gathers what you've noted and the questions to bring.
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This page draws on public guidance from:
General information, not medical advice. Every pregnancy is different, and your midwife or doctor knows yours. Last updated October 2026.